Something a little closer to home. Can Passover be with 14 days of the winter/summer equinox or does there have to be a new moon after the equinox and the the full moon associated with that month is the Passover the GOD would recognize? The one coming up has both sides using a full moon within a week of Mar:21 as Passover.
I tend to go with as late as possible as the camel trails would be hard and smooth rather than muddy and full of tripping hazards as well as the part of the OT that covers that first Passover.